It has been indicated that the phenotypic severity depended on the specific location of the variant, suggesting a genotype-phenotype correlation.[5] Recently, Chitayat-Hall syndrome, a rare condition characterized by distal arthrogryposis, intellectual disability, dysmorphic features, hypopituitarism, and particularly growth hormone deficiency,[8] was demonstrated to be another MAGEL2-related disorder.[9,10] Compared with the relatively higher incidence of PWS cases, SYS cases especially the fatal cases of SYS were rarely reported. Here, MAGEL2 is linked to Schaaf-Yang syndrome.